Medical examination tables are conventionally provided with various electrical components. One such common component includes one or more electrical outlets for plugging in accessories. Despite their convenience and utility, outlets on tables may be a source of leakage current. Leakage current is the current that can flow through a protective ground conductor to ground. In the absence of a grounding connection, leakage current could seek ground through a path that includes a patient's body.
This undesirable phenomenon is addressed conventionally by including an isolation transformer on the power supply to an accessory receptacle. The ground from the accessory receptacle is typically tied to the chassis of the table. Arranged as such, leakage current from the accessory seeks the transformer's secondary, and not earth ground. That is, leakage current from the accessory electrical receptacle seeks the secondary of the isolation transformer instead of an earth ground, thereby protecting patients and operators from closing the grounding circuit and receiving an electrical shock or other injury. Despite their effectiveness, however, such isolation transformers add complexity and additional manufacturing costs to tables so equipped. There is consequently a need for an improved manner of grounding leakage current.